CR系统在新生儿床边胸部摄影中的价值

目的评价计算机X线摄影在新生儿床边胸部摄影中的价值。方法收集整理新生儿床边胸部摄影344例,运用计算机图像处理技术对影像清晰度、对比度及病灶边缘密度进行调整、统计、归纳和分析,然后与传统X线检查进行对比。结果所有新生儿的床边胸部CR片均能达到满意的诊断要求,CR与传统方法照片相比曝光剂量低,且CR与传统方法照片对比图像质量提高。结论 CR新生儿床边胸片对比度、清晰度良好,病变显示清晰,诊断准确,与传统X线摄影相比具有较好的临床应用价值。     

床旁计算机X线摄影在大面积烧伤患者中应用效果的观察

大面积烧伤患者,由于不宜搬动等限制,床旁X线胸片已成为了解患者胸部病情的首选辅助检查。计算机X线摄影（CR）技术已在影像学检查中得到广泛应用,它在降低曝光剂量的同时使床旁胸片的成像质量明显提高,为临床提供了更加丰富、可靠的诊断依据。     

CR系统在婴幼儿摄影中的应用

计算机摄影（computed radiography．CR）技术，是使用可记录并由激光读出X线成像信息的成像板（imagingplate，IP）作为载体，经X线曝光及信息读出处理，形成数字式平片影像的技术。在基层医院放射科日常工作中，婴幼儿患者占相当比例，由于其解剖生理特点，患儿难与工作人员合作．给获得理想X线照片带来一定困难。本院自2004年9月引进CR系统行婴幼儿摄片，收到满意的影像效果，现就其临床应用价值报告如下。     

计算机X线摄影在床旁胸部摄影中的应用

床旁胸片是放射学检查中必不可少的一部分,但床旁胸片质量不易控制,计算机X线摄影(Computed Radiography,CR)系统作为一种新型的以X线为成像能源的数字式成像技术的出现,大大改善了胸部成像的方式,提高了影像质量,特别是床旁胸部摄影质量,对提高诊断水平起着重要作用。现收集我院自应用CR系统以来床旁胸部摄影510例进行回顾分析,现报告如下。     

体位对3~4岁儿童胸部数字X线摄影辐射剂量与图像质量的影响

目的观察不同体位对3～4岁儿童胸部数字X线摄影(DR)辐射剂量与图像质量的影响。方法将120例3～4岁患儿均分为仰卧前后位组(A组)、站立前后位组(B组)及站立后前位组(C组)各40例,行胸部DR检查;记录剂量面积乘积(DAP)和体表入射剂量(ESD),以视觉分级分析评分(VGAS)评价图像质量。结果 C组与B组DAP和ESD显著低于A组(P均0.05);B组VGAS显著低于C组和A组(P均0.05);而C组肺野面积显著大于B组和A组(P均0.05)。结论对3～4岁儿童行胸部DR检查时,体位对图像质量及辐射剂量存在一定影响;宜依序选择站立后前位、仰卧前后位及站立前后位。     

ClarityIQ的三大支柱技术解析及其对降低放射剂量的影响

<正>在以X线影像作为介导手段的介入性操作中,通常会面临两难困境———一方面,为保护患者和医护人员,需要降低X线剂量;另一方面,对于肥胖及外科手术高风险患者,为提高图像质量,以明确诊断和指导操作,又需要增加X线剂量。飞利浦公司最新推出的ClarityIQ技术成功实现了在保持同等图像质量的前提下大幅度降低X线辐射剂量。对于目前的X线设备,有众多降低X线剂量的方     

三种跟骨骨折影像检查方法的临床应用比较

背景：多层螺旋CT的广泛应用使受检者接受X线辐射剂量日益增多。如何优化CT扫描参数以减少受检者的X线吸收剂量是目前研究的热点。目的：通过比较跟骨骨折3种影像学检查表现,探讨DSA Innova 3D在跟骨骨折中的诊断价值。方法方法：回顾性分析本院收治经手术证实的20例跟骨骨折病例资料,以手术所见为金标准,由2名有经验的影像诊断医师以双盲法对DSA、螺旋CT及CR骨折表现及图像的噪声值、剂量指数等进行评分,对比分析20例跟骨骨折DSA、螺旋CT及CR表现、受检者接受的X线辐射剂量、体位要求高低及检查时间长短比较。结果：跟骨骨折部位、类型、关节面塌陷程度及骨折片移位情况显示如下：DSA下20例均能清晰显示;螺旋CT下18例清晰显示,2例不能清晰显示;CR下3例能清晰显示,17例未见显示。DSA、螺旋CT及CR的图像噪声值分别为16、20、30 d BA;受辐射剂量分别为0.023、4.6、0.046 m Gy。检查摆体时间：螺旋CT 220 s,CR 120s,DSA 20 s。检查时间：螺旋CT 12 s,DSA 0.8 s,CR 1 s。图像SNR：DSA 2.7,螺旋CT 3.71,CR4.0。结论：DSA Innova 3D图像比螺旋CT及CR更能清楚显示骨折部位、类型、严重度及移位情况,同时减少受检者接受X线辐射剂量及检查时间,体位要求低,图像质量好,值得推广。     

口腔数字成像系统投照剂量及角度的临床研究

目的:探讨口腔数字化成像系统X线的正确投照剂量和角度。方法:从我院口腔门诊患者中随机抽取健康志愿者20名,共拍摄数字牙片320张。采用传统根尖片的分角线投照技术分别拍摄牙列中各牙位的数字化牙片。拍摄时,患者的体位、水平角度和X线中心线与传统根尖片摄影方法相同。对每一牙位分别选择3组不同的投照剂量和垂直角度进行拍摄并记录患者拍摄牙位、投照剂量(即曝光时间)和垂直角度。统计确定每个牙位数字化牙片正确的投照角度和投照剂量。结果:与传统牙片比较,数字化牙片投照角度增加,其中以上颌后牙和下颌前牙角度增加较为明显。数字牙片的投照剂量较传统牙片明显减小,减少的幅度约为50％～80％。结论:数字化牙片拍摄时应适当增加投照角度,减少投照剂量。它可以大大减少患者暴露在X线中的时间并且降低拍摄牙片对人体的损害。     

《平片X线摄影数字成像系统》已出版

正由全军医学影像中心、全国学科排名位居前10位的南京军区南京总医院医学影像科(南京大学附属金陵医院)王骏主译的"平片X线摄影数字成像系统"出版发行。本书全面、系统地论述了平片X线摄影数字成像技术,从多角度反映了当今数字成像系统的实际,深层次广泛探讨了数字X线摄影成像系统的理论,充分体现了当今临床应用的最新成果。其内容包含数字X线摄影探测器、数字X线摄影的技术问题、数字系统的患者剂量评估、诊断放射学中的图像质量、数字X线摄影的实践、数字X摄影图像增强、数字X线摄影和图像存储与传输系统     

CR系统在乳腺钼靶摄影中的应用

目的：观察及评价CR系统在乳腺铝靶X线摄影中的应用价值。方法：IP板，MIEV铝靶X线机，轴位、斜位乳腺拍片，经CR系统后处理拍出激光照片。结果：45例中，良性肿瘤20例，恶性肿瘤25例，与手术后病理切片对比，诊断正确率90％（40／45）。结论：CR技术在诊断、鉴别诊断、早期发现乳腺肿瘤等方面作用突出。     

Digital radiography can reduce scoliosis x-ray exposure

Digital radiology is a new computerized system of acquiring x-rays in a digital (electronic) format. It possesses a greatly expanded dose response curve that allows a very broad range of x-ray dose to produce a diagnostic image. Potential advantages include significantly reduced radiation exposure without loss of image quality, acquisition of images of constant density irrespective of under or over exposure, and reduced repeat rates for unsatisfactory films. The authors prospectively studied 30 adolescents with scoliosis who had both conventional (full dose) and digital (full, one-half, or one-third dose) x-rays. They found digital made AP and lateral image with all anatomic areas clearly depicted at full and one-half dose. Digital laterals were better at full dose and equal to conventional at one-half dose. Cobb angles were easily measured on all one-third dose AP and on 8 of 10 one-third dose digital laterals. Digital clearly depicted the Risser sign at one-half and one-third dose and the repeat rate was nil in this study, indicating digital compensates well for exposure errors. The study indicates that digital does allow radiation dose to be reduced by at least one-half in scoliosis patients and that it does have improved image quality with good contrast over a wide range of x-ray exposure.     

Fluoroscopic exposure in modern spinal surgery

The widespread use of minimally invasive and other spinal procedures raises concern about the peroperative radiation exposure to surgeon and patient. The authors noted the fluoroscopy time and the radiation dose, as read from the image amplifier, in 95 spinal procedures. The results of this prospective study varied widely between different operations. Percutaneous surgery was associated with more exposure than open surgery. For instance, the average radiation dose per pedicle screw was 3.2 times higher with percutaneous insertion than with an open approach. Therefore, efforts to reduce fluoroscopy time and radiation exposure should be made when using minimally invasive percutaneous surgical techniques. Preventive measures for the surgeon, such as lead aprons and gloves, thyroid shields, radioprotective glasses and staying away from the beam are recommended. Still from the surgeon's view-point, source inferior positioning of the image amplifier is indicated for the AP view, as well as monitoring of the radiation exposure. Finally, the difference in fluoroscopy time and radiation exposure between surgeons for the same procedure stresses the fact that peroperative radiation may be reduced by simple awareness and by training.     

New developed urological protocols for the Uro Dyna-CT reduce radiation exposure of endourological patients below the levels of the low dose standard CT scans

Purpose

Cross-sectional imaging by computed tomography (CT) is associated with higher radiation dose compared to plain X-ray. The Uro Dyna-CT provides CT-like images in the endourological operating room. Our aim was to reduce the radiation exposure of endourological patients with the Uro Dyna-CT and optimize the cross-sectional image quality.

Materials and methods

For the hard contrast protocol, two artificial stones were placed in a Rando–Alderson phantom’s left kidney region. Relevant parameters of the standard abdomen protocol were changed. After each modification, two urologists subjectively evaluated the image quality. We developed two customized protocols (standard, low-dose) for hard contrast imaging. To optimize the examination protocol for soft tissue imaging a standardized cone beam phantom was used. Parameters of the preset high-resolution protocol were changed to develop a protocol with similar objective image quality but lower radiation dose. To evaluate the effective radiation dose we embedded 129 thermoluminescence dosimeters in the kidney and ureter region of the Rando–Alderson phantom and performed each protocol five times (stone, soft tissue) and ten times (low-dose protocol). Mean effective dose values per 3D-examination were calculated.

Results

We detected a dose area product (DAP) 776.2 (standard) and 163.5 μGym² (low-dose) for the stone protocols with an effective dose of 1.96 and 0.33 mSv, respectively. The soft tissue protocol produced a DAP of 5,070 μGym² and an effective dose of 7.76 mSv.

Conclusion

Our newly developed examination protocols for the Uro Dyna-CT provide CT-like image quality during urological interventions with low radiation dose.     

Dose effects and image quality: Is there any influence by bearing devices in whole-body computed tomography in trauma patients?

Background

Stable bearing devices are often utilized by prehospital first responders in modern management of severely injured patients. It is not known whether these devices influence radiation exposure or image quality in whole-body computed tomography (WBCT). Additionally, manufacturers currently provide no specifications concerning these criteria. This investigation analyzed the influence of nine different bearing devices on these specified criteria.

Methods

The influence of nine different bearing devices on radiation exposure and image quality in WBCT was investigated. The dose-length-product (DLP₁₀₀) was obtained through use of a CT-ionisation chamber placed in the centre of a 32 cm CT-phantom and compared with a reference value. Moreover, the results were calculated as effective dose data E (mSv). The image quality was assessed by three expert radiologists using the following scoring scale (0 = no artefacts; 1 = minor artefacts; 2 = clearly artefacts; 3 = massive artefacts).

Results

Out of nine bearing devices examined, four showed significantly higher (2.5–4.5%, p < 0.05) DLP₁₀₀ and five showed no significant difference between DLP₁₀₀ and the reference value. The image quality was classified in the categories “0”, “1”, “2” and “3” in 4, 3, 1 and 1 case, respectively.

Conclusions

In diagnostic producers using WBCT, bearing devices may be associated with relevant increases in radiation dose and can affect the image assessability. Some bearing devices are associated with no significant influence on radiation dose and reduction of image quality. Considering all results to get the best balance between image quality and radiation dose, aluminium and metal-free devices should be preferred.     

Does the choice of mobile C-arms lead to a reduction of the intraoperative radiation dose?

IntroductionMobile C-arm imaging is commonly used in operating rooms worldwide. Especially in orthopaedic surgery, intraoperative C-arms are used on a daily basis. Because of new minimally-invasive surgical procedures a development in intraoperative imaging is required. The purpose of this article is investigate if the choice of mobile C-arms with flat panel detector technology (Siemens Cios Alpha and Ziehm Vision RFD) influences image quality and dose using standard, commercially available test devices.Materials and methodsFor a total of four clinical application settings, two zoom formats, and all dose levels provided, the transmission dose was measured and representative images were recorded for each test device. The data was scored by four observers to assess low contrast and spatial resolution performance. The results were converted to a relative image quality figure allowing for a direct image quality and dose comparison of the two systems.ResultsFor one test device, the Cios Alpha system achieved equivalent (within the inter-observer standard error) or better low contrast resolution scores at significantly lower dose levels, while the results of the other test device suggested that both systems achieved similar image quality at the same dose. The Cios Alpha system achieved equivalent or better spatial resolution at significantly lower dose for all application settings except for Cardiac, where a comparable spatial resolution was achieved at the same dose.ConclusionThe correct choice of a mobile C-arm is very important, because it can lead to a reduction of the intraoperative radiation dose without negative effects on image quality. This can be a big advantage to reduce intraoperative radiation not only for the patient but also for the entire OR-team.     

Frontal sinus repair through a frontalis rhytid approach

Abdominal wall computed tomography angiography (CTA) is used to guide preoperative planning and intraoperative technique for deep inferior epigastric artery perforator free flap breast reconstructive surgery. This study considers the amount of radiation delivered to the patient, outlining how scan parameters can be optimized to minimize the radiation exposure whilst maintaining image quality. Results of scan parameters and dose reports for 34 patients undergoing abdominal wall CTA are compared with those patients undergoing routine abdominal computed tomography. The links between computed tomography dose quantities are explained, including their conversion to effective dose (in mSv) and risk as the probability for inducing deterministic effects (eg, skin burns) and stochastic effects (ie, cancer induction). The mean effective dose by using our technique for routine abdominal computed tomography is 9.9 and for abdominal wall CTA is 6.0 mSv. All doses are far below the thresholds for deterministic effects to the skin. Abdominal wall CTA can be justified before major reconstructive surgery if the surgeon believes that the very low estimated risk of fatal radiation-induced cancer (1 in 4270 for 6 mSv) is outweighed by the benefits.     

Clinical testing of an image memory in peroperative roentgen diagnosis]

The relatively high radiation exposure when applying mobile X-ray image intensifiers to surgical radiology can be distinctly reduced by the ultilzation of an electronic image memory, which makes visible as long as you like the last fluoroscopic image of a fluoroscopic scene on the viewing monitor without switching on the X-ray tube. As an average over various surgical examinations, the dose reduction compared with facilities lacking these image memories amounts to about 30%.     

Radiation exposure with use of the inverted-c-arm technique in upper-extremity surgery

BACKGROUND: Intraoperative fluoroscopy is commonly used in surgical procedures on upper extremities. We compared radiation exposure from two possible positions of the mobile digital fluoroscopy unit (c-arm): (1) the standard technique, with the x-ray tube down (near the floor) and the image intensifier at the top of the c-arm, and (2) the inverted position, in which the image intensifier is used as a table and the x-ray tube is up. METHODS: A commercially available c-arm was used to irradiate a phantom hand in one of three configurations. In the first, the phantom hand was placed on an armboard equidistant from the x-ray tube and the image intensifier with the beam directed upward. In the second, the c-arm was inverted with the beam directed downward and the image intensifier used as a table. The third configuration was identical to the second except that a magnified image was used. Radiation exposure was measured at four locations corresponding to the approximate position of the surgeon's head, chest, and groin and the patient's hand. RESULTS: The amount of radiation exposure to both the surgeon and the patient was significantly less when the c-arm was used in the inverted position (p < 0.0001). The dose rate to the patient's hand was reduced by 59%. The radiation exposure to the surgeon's head, body, and groin with the inverted-c-arm technique was 67%, 45%, and 15% of the measured doses with the x-ray-tube-down configuration. When we used the magnification mode of the image intensifier, with its correspondingly smaller field size, the doses were further reduced to 46%, 32%, and 11% of the standard-configuration values. CONCLUSIONS: Use of the inverted-c-arm technique with the image intensifier as an operating table can significantly reduce radiation exposure to the surgeon and the patient during surgical procedures on upper extremities.     

X-ray dose reduction in examination of infant's hip with image-intensifier-fluoroscopy-system (author's transl)

An image intensifier--70mm camera--fluoroscopy system combined with a conventional X-ray tube is used for routine examination of the infant's hip. The high quality of 85% of these 70mm exposures makes immediate diagnostic interpretation possible. An even higher percentage can be achieved by most exact positioning of the patients. Apart from the radiation protection of the gonades, the X-ray skin dose of the primary beam is reduced by 90-95% compared with full size radiography using film screen combinations. This exposure technique can certainly be used not only for the examination of the infant's hip.